package com.ufida.ids.util;

import java.security.MessageDigest;

public class CipherUtil{    
    
    //十六进制下数字到字符的映射数组    
    private final static String[] hexDigits = {"0", "1", "2", "3", "4",    
        "5", "6", "7", "8", "9", "a", "b", "c", "d", "e", "f"};    
       
    public static String generatePassword(String inputString){    
        return encodeByMD5(inputString);    
     }    
        
         
    public static boolean validatePassword(String password, String inputString){    
        if(password.equals(encodeByMD5(inputString))){    
            return true;    
         } else{    
            return false;    
         }    
     }    
       
    private static String encodeByMD5(String originString){    
        if (originString != null){    
            try{    
                //创建具有指定算法名称的信息摘要    
                 MessageDigest md = MessageDigest.getInstance("MD5");    
                //使用指定的字节数组对摘要进行最后更新，然后完成摘要计算    
                byte[] results = md.digest(originString.getBytes());    
                //将得到的字节数组变成字符串返回    
                 String resultString = byteArrayToHexString(results);    
                return resultString.toUpperCase();    
             } catch(Exception ex){    
                 ex.printStackTrace();    
             }    
         }    
        return null;    
     }    
       
    private static String byteArrayToHexString(byte[] b){    
         StringBuffer resultSb = new StringBuffer();    
        for (int i = 0; i < b.length; i++){    
             resultSb.append(byteToHexString(b[i]));    
         }    
        return resultSb.toString();    
     }    
        
       
    private static String byteToHexString(byte b){    
        int n = b;    
        if (n < 0)    
             n = 256 + n;    
        int d1 = n / 16;    
        int d2 = n % 16;    
        return hexDigits[d1] + hexDigits[d2];    
     }   
    
    public static void main(String[] args) {
    	String pwd1="123#^^$***";    
        String pwd2="";    
        System.out.println("未加密的密码:"+pwd1);    
       //将123加密    
        pwd2 = CipherUtil.generatePassword(pwd1);    
        System.out.println("加密后的密码:"+pwd2);    
           
        System.out.print("验证密码是否下确:");    
       if(CipherUtil.validatePassword(pwd2, pwd1)) {    
            System.out.println("正确");    
        }    
       else {    
            System.out.println("错误");    
        }    

	}
}  